: Non-breeeding. mid Jun-mid Jul anywhere on saltwater but most frequently on the fringes of active seabird colonies.
: Complex. mid May-early June mostly through the with from early May but also where we have few data. late Jul-early Sep in the where birds arrive early and molt before continuing their . late Sep-early Nov with to early Dec, mostly with passage detectable from Schoodic Point.
: mid Dec-mid Jan off Schoodic Point and Sand Beach/Otter Point.
There are no records at any season from freshwater.
Miscellany: Bonaparte's Gull is the only one of the world's gulls that usually nests in trees.
Last Updated: April 25th, 2022